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i2c.inc
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;
; ========================================================================
; i2c.inc
; i2c library file
; 001 27-09-02 Source from http://www.piclist.com/techref/microchip/i2c87xjs.htm (John Sand)
; 002
; ========================================================================
;
;
; See i2c_def.inc
;
; External provides :
; I2C_Start
; I2C_Address
; I2C_Status (flags)
;
; The terms sync and async are used here to distinguish between a busy
; waiting implementation (exits when all data ready) and a state machine
; implementation to be inserted in-the-loop (i.e. typically as would be
; nescessary in a ISR).
;
;
; Remember to have SDA and SCL tris'd to inputs.
;-----------------------------------------------------------------------
CODE_SIZE_I2C_START
; ---------------------------------------------------
; M A S T E R S Y N C
; ---------------------------------------------------
ifdef Iwer2C_MASTER_SYNC_2
I2C_Start
SetBank0
bcf PIR1,SSPIF
SetBank1
bsf SSPCON2 & FORCE_7_BIT_ADR, SEN ; send i2c START condition [S] bit
SetBank0
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
btfss PIR1,SSPIF ; start bit cycle complete?
goto $-1
bcf PIR1,SSPIF
return
I2C_Stop
SetBank0
bcf PIR1,SSPIF
SetBank1
bsf SSPCON2 & FORCE_7_BIT_ADR, PEN ;send i2c STOP [P] bit
SetBank0
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
btfss PIR1,SSPIF ; Stop clock complete ?
goto $-1
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
bcf PIR1,SSPIF
return
I2C_AckWait
SetBank0
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
btfss PIR1, SSPIF ; 9th clock complete ?
goto $-1
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
bcf PIR1, SSPIF
return
I2C_MasterInit
; SSPCON<5> SSPEN
; SSPCON<3:0> '0110' = I2C Slave mode, 7-bit address
; SSPCON<3:0> '1000' = I2C Master mode, clock = FOSC / (4 * (SSPADD+1))
;
movlw b'00101000' ; Set SSPEN
movwf SSPCON ;=0x028
bcf PIR1, SSPIF
SetBank1
movlw b'10000000'
movwf SSPSTAT & FORCE_7_BIT_ADR
movlw b'01100000'
movwf SSPCON2 & FORCE_7_BIT_ADR
movlw b'00001010'
movwf SSPADD & FORCE_7_BIT_ADR
SetBank0
return
I2C_Test
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
SetBnkF SSPCON2
setc
btfss SSPCON2 & FORCE_7_BIT_ADR, ACKSTAT
clrc
SetBank0
;
skpnc
bsf I2C_TxStatus, I2C_ERROR_NACK
return
; I2C_MasterSyncWrite
; ---------------------------------------------------
; Transmits databyte to specified address.
I2C_MasterSyncWrite
call I2C_Start
movf I2C_TxAddress, W
movwf SSPBUF
call I2C_AckWait
call I2C_Test
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
movf I2C_TxCommand, W
movwf SSPBUF
call I2C_AckWait
call I2C_Test
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
decfsz I2C_TxNofBytes, F
goto tx_data
MSW_Ends
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
call I2C_Stop
return
tx_data
movf I2C_TxData, W
movwf SSPBUF
call I2C_AckWait
call I2C_Test
goto MSW_Ends
endif
ifdef I2C_MASTER_SYNC
I2C_MasterSyncInit
; SSPCON<5> SSPEN
; SSPCON<3:0> '0110' = I2C Slave mode, 7-bit address
; SSPCON<3:0> '1000' = I2C Master mode, clock = FOSC / (4 * (SSPADD+1))
;
movlw b'00101000' ; Set SSPEN
movwf SSPCON ;=0x028
bcf PIR1, SSPIF
SetBank1
movlw b'10000000'
movwf SSPSTAT & FORCE_7_BIT_ADR
movlw b'01100000'
movwf SSPCON2 & FORCE_7_BIT_ADR
movlw b'00001010'
movwf SSPADD & FORCE_7_BIT_ADR
SetBank0
return
#define I2C_MASTER_ASYNC
I2C_MasterSyncWrite
bsf I2C_Public, I2C_TX_START
MSW_loop
clrwdt
call I2C_MasterAsyncEngine
btfsc I2C_Public, I2C_TX_START
goto MSW_loop
return
endif
; ---------------------------------------------------
; M A S T E R A S Y N C
; ---------------------------------------------------
ifdef I2C_MASTER_ASYNC
; Storage used :
;I2C_Public
;I2C_TxJumpVector
;I2C_TxIndex
;I2C_TxNofBytes ; Nof bytes out including the address, I2C_TxNofBytes < 128d
;I2C_TxAddress
;I2C_TxCommand ; Indirectly for I2C_TxNofBytes > 1
;I2C_TxData ; Indirectly for I2C_TxNofBytes > 2
I2C_MasterAsyncInit
; SSPCON<5> SSPEN
; SSPCON<3:0> '0110' = I2C Slave mode, 7-bit address
; SSPCON<3:0> '1000' = I2C Master mode, clock = FOSC / (4 * (SSPADD+1))
;
movlw b'00101000' ; Set SSPEN
movwf SSPCON ;=0x028
bcf PIR1, SSPIF
SetBank1
movlw b'10000000'
movwf SSPSTAT & FORCE_7_BIT_ADR
movlw b'01100000'
movwf SSPCON2 & FORCE_7_BIT_ADR
movlw b'00001010'
movwf SSPADD & FORCE_7_BIT_ADR
SetBank0
return
; I2C_MasterAsyncEngine
; ---------------------------------------------------
;
ForcePageAlign .10
I2C_MasterAsyncEngine
I2C_MAW movlw I2C_MAW / 0x100
movwf PCLATH
;
movf I2C_TxJumpVector, W
addwf PCL, F
;
I2C_MAW_IDLE equ .0
goto I2C_MawIdle
I2C_MAW_BUSY equ .1
goto I2C_MawBusy
I2C_MAW_FINISHING equ .2
goto I2C_MawFinishing
if I2C_MAW / 0x0100 != $ / 0x0100
error "***** Page fault #0276 *****"
endif
; I2C_MawIdle
; ----------------------------------------
; Wait for client flags to start
I2C_MawIdle
btfss I2C_Public, I2C_TX_START
goto I2C_MawEnds
; User go. Initiate i2c start
bcf PIR1,SSPIF
SetBank1
bsf SSPCON2 & FORCE_7_BIT_ADR, SEN ; i2c START condition
SetBank0
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
clrf I2C_TxIndex
movlw I2C_MAW_BUSY
movwf I2C_TxJumpVector
goto I2C_MawEnds
; I2C_MawBusy
; ----------------------------------------
; Transmitting and waiting....
I2C_MawBusy
btfss PIR1,SSPIF ;cycle complete?
goto I2C_MawEnds
bcf PIR1,SSPIF
; Figure out if there are more data bytes
;
decf I2C_TxNofBytes, F
btfsc I2C_TxNofBytes, BIT7 ; Stop when reaching -1 (this is the 128 limit)
goto setup_stop
; Load databyte and write to transmitter register "SSPBUF"
;
movf I2C_TxIndex, W
addlw I2C_TxAddress
movwf FSR
movf INDF, W
movwf SSPBUF ; Data transmission starts
setup_next
incf I2C_TxIndex, F
goto I2C_MawEnds
setup_stop
; No more data, start i2c STOP condition
SetBank1
bsf SSPCON2 & FORCE_7_BIT_ADR, PEN ;send i2c STOP [P] bit
SetBank0
movlw I2C_MAW_FINISHING
movwf I2C_TxJumpVector
goto I2C_MawEnds
; I2C_MawFinishing
; ----------------------------------------
; Waiting for end of STOP, and then cleaning up.
; Clears "I2C_TX_START" to signal tx complete to host.
;
I2C_MawFinishing
btfss PIR1,SSPIF ; STOP complete ?
goto I2C_MawEnds
; STOP is complete
bcf PIR1,SSPIF
bcf I2C_Public, I2C_TX_START
;
movlw I2C_MAW_IDLE
movwf I2C_TxJumpVector
I2C_MawEnds
return
endif ; ifdef I2C_MASTER_ASYNC
; ---------------------------------------------------
; S L A V E A S Y N C
; ---------------------------------------------------
ifdef I2C_SLAVE_ASYNC
; I2C_SlaveInit
; ---------------------------------------------------
I2C_SlaveInit
movlw b'00110110' ; 7bit address slave
movwf SSPCON ;=0x028
bcf PIR1, SSPIF
SetBank1
movlw b'10000000'
movwf SSPSTAT & FORCE_7_BIT_ADR
movlw b'01100000'
movwf SSPCON2 & FORCE_7_BIT_ADR
movlw I2C_SLAVE_ADRESS
movwf SSPADD & FORCE_7_BIT_ADR ; 7 bit address
SetBank0Auto
movf SSPBUF, W ; Clear any buffer full (BF) flag.
bcf SSPCON, SSPOV ; Clear any overflow flag.
; State machine
;
clrf I2C_SarJumpvector
clrf I2C_Public
return
; I2C_SlaveAsyncRead
; ---------------------------------------------------
; Supports 1 or 2 data bytes after address.
; ToDo : Slave write
; ToDo : Support for length field after command (Command with bit 7 set)
;
I2C_SlaveAsyncRead
I2C_SAR movlw I2C_SAR / 0x100
movwf PCLATH
;
movf I2C_SarJumpvector, W
addwf PCL, F
;
I2C_SAR_STOPPED equ .0
goto I2C_SarStopped
I2C_SAR_IDLE equ .1
goto I2C_SarIdle
I2C_SAR_CMD equ .2
goto I2C_SarCmd
I2C_SAR_DATA equ .3
goto I2C_SarData
I2C_SAR_WAIT_STOP equ .4
goto I2C_SarWaitStop
if I2C_SAR / 0x0100 != $ / 0x0100
messg "Page fault #0225"
endif
; I2C_SarStopped
; ----------------------------------------
; Wait for client ready
I2C_SarStopped
; Stop receiving until previous data are processed by subscriber
;
btfsc I2C_Public, I2C_RX_COMPLETE
goto I2C_SarEnds
; Cleanup any junk flags (FIXIT)
;
movf SSPBUF, W ; Clear any buffer full (BF) flag.
bcf SSPCON, SSPOV ; Clear any overflow flag.
bcf PIR1, SSPIF
movlw I2C_SAR_IDLE
movwf I2C_SarJumpvector
goto I2C_SarEnds
; I2C_SarIdle
; ----------------------------------------
; Wait for address match
I2C_SarIdle
; Stop receiving until previous data are released
;
btfss PIR1, SSPIF
goto I2C_SarEnds
; Address match
;
bcf PIR1, SSPIF
movf SSPBUF, W ; Clear any buffer full (BF) flag.
;
movlw I2C_SAR_CMD
movwf I2C_SarJumpvector
; I2C_SarCmd
; ----------------------------------------
; Load first data byte
I2C_SarCmd
btfss PIR1, SSPIF
goto I2C_SarEnds
bcf PIR1, SSPIF
; Got command
movf SSPBUF, W ; Clears BF
movwf I2C_RxCommand
; More bytes ??
;
call I2C_GetNofBytesFromCommand
movwf I2C_RxNofBytes
decfsz I2C_RxNofBytes, F
goto more_bytes
; No, we are done.
;
movlw I2C_SAR_WAIT_STOP
movwf I2C_SarJumpvector
goto I2C_SarEnds
more_bytes
movlw I2C_SAR_DATA
movwf I2C_SarJumpvector
goto I2C_SarEnds
; I2C_SarData
; ----------------------------------------
; Load first data byte
I2C_SarData
btfss PIR1, SSPIF
goto I2C_SarEnds
; Got data
movf SSPBUF, W ; Clears BF
movwf I2C_RxData
bcf PIR1, SSPIF
movlw I2C_SAR_WAIT_STOP
movwf I2C_SarJumpvector
goto I2C_SarEnds
; I2C_SarWaitStop
; ----------------------------------------
I2C_SarWaitStop
SetBnkF SSPSTAT
btfss SSPSTAT & FORCE_7_BIT_ADR, P
goto I2C_SarEndsBank0
SetBank0Auto
; There were a stop condition, publish to user
;
bsf I2C_Public, I2C_RX_COMPLETE
MDisableI2CIntr
movlw I2C_SAR_STOPPED
movwf I2C_SarJumpvector
goto I2C_SarEnds
I2C_SarEndsBank0
SetBank0Auto
I2C_SarEnds
return
endif
; ---------------------------------------------------
; S L A V E A S Y N C
; ---------------------------------------------------
ifdef I2C_SLAVE_ASYNC_ISR
; I2C_SlaveInit
; ---------------------------------------------------
I2C_SlaveInit
movlw b'00110110' ; 7bit address slave
movwf SSPCON ;=0x028
bcf PIR1, SSPIF
SetBank1
movlw b'10000000'
movwf SSPSTAT & FORCE_7_BIT_ADR
movlw b'01100000'
movwf SSPCON2 & FORCE_7_BIT_ADR
movlw I2C_SLAVE_ADRESS * 2
movwf SSPADD & FORCE_7_BIT_ADR ; 7 bit address
SetBank0
; State machine
;
clrf I2C_SarJumpvector
clrf I2C_Public
I2C_Restart
movf SSPBUF, W ; Clear any buffer full (BF) flag.
bcf SSPCON, SSPOV ; Clear any overflow flag.
return
; I2C_SlaveAsyncRead
; ---------------------------------------------------
; Supports 1 or 2 data bytes after address.
; ToDo : Slave write
; ToDo : Support for length field after command (Command with bit 7 set)
;
I2C_SlaveAsyncRead
I2C_SAR movlw I2C_SAR / 0x100
movwf PCLATH
;
movf I2C_SarJumpvector, W
addwf PCL, F
;
I2C_SAR_IDLE equ .0
goto I2C_SarIdle
I2C_SAR_CMD equ .1
goto I2C_SarCmd
I2C_SAR_DATA equ .2
goto I2C_SarData
I2C_SAR_WAIT_STOP equ .3
goto I2C_SarWaitStop
if I2C_SAR / 0x0100 != $ / 0x0100
messg "Page fault #0225"
endif
; I2C_SarIdle
; ----------------------------------------
; Wait for address match
I2C_SarIdle
; Stop receiving until previous data are released
;
btfss PIR1, SSPIF
goto I2C_SarEnds
; Address match
;
bcf PIR1, SSPIF
movf SSPBUF, W ; Clear any buffer full (BF) flag.
;
SetBnkF SSPSTAT
bcf SSPSTAT & FORCE_7_BIT_ADR, P
SetBank0
movlw I2C_SAR_CMD
movwf I2C_SarJumpvector
; I2C_SarCmd
; ----------------------------------------
; Load first data byte
I2C_SarCmd
btfss PIR1, SSPIF
goto I2C_SarEnds
; Got command
bcf PIR1, SSPIF
movf SSPBUF, W ; Clears BF
movwf I2C_RxCommand
; More bytes ??
;
call I2C_GetNofBytesFromCommand
movwf I2C_RxNofBytes
decfsz I2C_RxNofBytes, F
goto more_bytes
; No, we done.
;
movlw I2C_SAR_WAIT_STOP
movwf I2C_SarJumpvector
goto I2C_SarEnds
more_bytes
movlw I2C_SAR_DATA
movwf I2C_SarJumpvector
goto I2C_SarEnds
; I2C_SarData
; ----------------------------------------
; Load first data byte
I2C_SarData
btfss PIR1, SSPIF
goto I2C_SarEnds
bcf PIR1, SSPIF
; Got data
movf SSPBUF, W ; Clears BF
movwf I2C_RxData
bsf I2C_Public, I2C_RX_COMPLETE
MDisableI2CIntr
movlw I2C_SAR_IDLE ; I2C_SAR_WAIT_STOP
movwf I2C_SarJumpvector
goto I2C_SarEnds
; I2C_SarWaitStop
; ----------------------------------------
I2C_SarWaitStop
SetBnkF SSPSTAT
btfss SSPSTAT & FORCE_7_BIT_ADR, P
goto I2C_SarEndsBank0
SetBank0
; There were a stop condition, publish to user
;
; delete
btfss PIR1, SSPIF
goto NoFuzz2
bcf PIR1, SSPIF
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
NoFuzz2
movlw I2C_SAR_IDLE
movwf I2C_SarJumpvector
goto I2C_SarEnds
I2C_SarEndsBank0
SetBank0
I2C_SarEnds
return
endif
ifdef I2C_RxCommand
; I2C_GetNofBytesFromCommand
; ---------------------------------------------------
; Returns nof bytes matching value in "I2C_RxCommand"
; ToDo : Switch table as function of adress.
I2C_GetNofBytesFromCommand
if ICE ; -------------------------------------
nop ; Breakpoint :
nop ;
endif ; -------------------------------------
if I2C_GetNofBytesFromCommand / 0x100 != I2C_SAR / 0x100
movlw I2C_GetNofBytesFromCommand / 0x100
movwf PCLATH
endif
movf I2C_RxCommand, W
andlw b'00000111'
addwf PCL, F
retlw I2C_725_LEVEL_CHANGED_CMD_LEN - 1 ;I2C_725_CMD_LEVEL_LOW
retlw I2C_725_LEVEL_CHANGED_CMD_LEN - 1 ;I2C_725_CMD_LEVEL_HIGH
retlw 0x01
retlw 0x01
retlw 0x01
retlw 0x01
retlw 0x01
retlw 0x01
if I2C_GetNofBytesFromCommand / 0x0100 != $ / 0x0100
error "Page fault"
endif
endif
CODE_SIZE_I2C equ $ - CODE_SIZE_I2C_START